Discharge electrode tensioning means

ABSTRACT

Discharge electrode tensioning means and more particularly a means for post-tensioning a discharge electrode used in a precipitator and aligning such electrodes to maintain a spaced charge.

United States Patent Humphreys [451 Nov. 28, 1972 [54] DISCHARGE ELECTRODE TENSIONING MEANS [72] Inventor: Wendell Lewis Humphreys, 2364 Ganesha Avenue, Altadena, Calif. 91001 [22] Filed: Oct. 22, 1969 21 Appl. No.: 868,358

[52] US. Cl. ..55/147, 55/148, 55/151, 55/129, 248/228 [51] Int. Cl ..B03c 3/41 [58] Field of Search ..55/112,140,141,147,148, 55/150,151,152,153,129;160/349,166, 168, 173; 248/340, 228

[56] References Cited UNITED STATES PATENTS 609,414 8/1898 Couch ..248/340 2,688,375 9/1954 Marriott ..55/147 2,751,036 6/1956 Busfield ..55/147 X Schlesinger 1 60/349 2,803,298 8/1957 3,140,557 7/1964 Albrycht ..248/340 3,463,432 8/1969 Ptak ..248/ 228 3,483,670 12/1969 Quintilian et al. ..55/ 148 X 1,325,136 12/1919 Bradley ..55/157 1,382,037 6/1921 Welch ..55/151 X 3,354,617 11/1967 Hoisington et al ..55/112 X FOREIGN PATENTS OR APPLICATIONS 76,540 4/1948 Czechoslovakia ..55/151 578,513 6/1933 Germany ..248/228 558,171 12/1943 Great Britain ..55/148 Primary Examiner-Dennis E. Talbert, Jr. Attorney-E. Wallace Breisch [57] ABSTRACT Discharge electrode tensioning means and more particularly a means for post-tensioning a discharge electrode used in a precipitator and aligning such electrodes to maintain a spaced charge,

11 Claims, 5 Drawing Figures PATENTEDwuvze 1912 3103799 INVENTOR.

WENDELJ. L. HUMPHREYS DISCHARGE ELECTRODE TENSIONING MEANS In an electrostatic precipitator of a type which is used for the large scale removal of finely divided material from gases associated with industrial processes and operation, the laden gas is passed in a stream through an electrostatic field of force produced by maintaining an electrostatic potential or high voltage corona discharge between suitable electrodes. A common form of such suitable electrodes includes a plurality of corona discharge electrodes, which are elongated flexible vertically disposed members, hereinafter referred to as wires, and a plurality of flat collector plates at positive or ground potential. Rows of corona discharge wires are disposed in planes parallel to and alternating with such plates in multi layers sandwich fashion.

Precipitators of the type described hereinabove are plagued by the fact that the wires cannot be held stationary. They tend to swing to and fro as a group or vibrate individually, relative to the collecting electrode or plates, causing the gap between the plates and the wires to vary. This variance is often referred to in this art as the swinging field effect." Swinging field effect may be caused by the impact of the gas flowing through the precipitator, or the electromagnetic or electrostatic forces that exist in the electrostatic precipitator. In any event, the swinging is undesirable because not only do the electrostatic and electromagnetic field characteristics vary but the swinging may result in a positive arcing across between the wires and the plates with consequent damage to either or both and as such, a marked decrease in the efficiency of operation of the precipitator.

The most suitable system for relieving the above described swinging field effect is to post tension the discharge wire such as by a weight attached to the lower end thereof, however, even with such post tensioning it has been found to be desirable to additionally brace the discharge electrodes in the transverse directions thereof. The prior art systems for post tensioning and bracing the discharge electrodes have proved to be inadequate for a variety of reasons, for example; high material cost and/or complicated and lengthy installation.

By use of the alignment grid system of the present invention which includes interlocking weights and alignment bars, advantages are apparent over previously used designs, for example: the weights and grid system cannot displace independently; a reduction in material quantity results; and the installation of the grid system of this invention is greatly simplified over systems heretofore in use.

These and other objects and advantages of this invention will become more readily apparent from a reading of the following description and drawings in which:

FIG. 1 is a perspective view, with parts broken away, of an electrostatic precipitator which includes the weighted grid system of the present invention;

FIG. 2 is an enlarged side view, partly in section, of a portion of a row of tensioning weights constructed in 4ofFlG. 2; and

FIG. 5 is an enlarged side view, partly in section, of another embodiment of a tensioning weight constructed in accordance with the principles of this invention.

An electrostatic precipitator (FIG. 1) is shown as comprising a housing or shell having the usual side walls and roof and a gas inlet l2 for gases which are laden with particulate material to be separated electrostatically. A clean gas outlet (not shown) is provided on the opposite side of casing 10 from inlet 12, for the exit of gases from which the particulates have been removed. A perforated diffuser plate 14 is normally located over the gas inlet to insure proper distribution of the gas throughout the precipitator. Housing 10 is reinforced by the usual struts and sway braces to stabilize the precipitator from any horizontal forces applied thereto.

A plurality of corona discharge wires extend downwardly from an ionizer assembly 22 located downwardly adjacent the roof 24 of housing 10. Ionizer assembly 22 is spaced from roof 24 by any suitable insulating material disposed therebetween such that electric power from a high voltage source (not shown) can be supplied to assembly 22 without electrifying housing 10. Wires 20 are arranged in a plurality of elongated equally spaced rows 26 which are generally parallel to the flow of gas through housing 10. A plurality of positively charged vertical collector plates 28 are disposed between alternate rows 26 and grounded at the housing 10. Wires 20 are negatively charged thereby setting up an electrostatic field of force between the positive electrode plates 28 and the negative electrodes wires 20. The lower end of wires 20 are located downwardly adjacent the lower end of plates 28 a sufficient distance to allow clearance for a wire stabilizing frame 29 of this invention.

The bottom of housing 10 is comprised of a plurality of hoppers 30 having the usual downwardly inclined sides for the collection of dust and other particulate materials that fall from plates 28. The plates 28 are provided with the usual rappers (not shown) for jarring the plates to cause the collected material from the plates 28 to fall into the hoppers 30.

Inasmuch as the invention resides in the means of stabilizing the discharge wires 20 and the balance of the elements mentioned hereinabove are well known in the art, further description of such elements is not believed to be warranted.

As hereinafter described in detail, the wire stabilizing frame 29 comprises: a plurality of tensioning weights 32 suspended from the lower end of wires 20; weight alignment bars 34 which extend axially along rows 26 and interlock with the tensioning weights 32 of a respective row 26; and alignment spacer bars 36 which extend transversely of rows 26 and are secured to bars 34. With such a stabilizing frame 29 as broadly described hereinabove the swinging field effect of unstabilized wire discharge electrodes is greatly reduced or eliminated entirely, thereby resulting in efficiency of operation of the electrostatic precipitator.

A weight 32 includes an elongated main body portion 38 which has an upwardly extended generally bullet shaped cross section. A slot 40 extends inwardly from each axial end of body portion 38 and terminates intermediate the respective ends of portion 38 and the vertical centerline thereof as shown in FIG. 2. Slot 40 is shown as extending along the longitudinal centerline of body portion 38 and comprises a lower section 42, shown as having a generally square cross section, located intermediate the vertical ends of body portion 38 and an upper section 44, shown as having a generally rectangular cross section which is oriented such that the longer side thereof extends between section 42 and the uppermost surface of portion 38. The length of the short side of section 44 is less than the length of the upper side of section 42. At the intermost ends of slot 40, the upper end of section 42 is expanded upwardly in the general shape of frustrum of a right circular cone to form a seat portion 46. As shown, the length of body portion 38 and the dimensions of slot 40 are such that two adjacent wires in a row 26 are received by respective slots and seated within the expanded portion 46 of the respective slots 40 such that once seated in seat'portions 46, the wires 20 are parallel to one another and are relatively immovable with respect to one another until unseated. Wires 20 have suitable electrode ferrules 48 at the lower ends thereof which are received within lower section 42 of slot 40. The upper end of ferrule 48 is engageable with seat portion 46. 1

Weight 32 additionally includes an elongated, axially extending generally rectangular cross-section interlocking portion 50 thereof which depends from the lower side of body portion 38 and is located intermediate the axial ends thereof. Portion 50 has an axially extending interlocking slot 52 therethrough, which comprises axially aligned generally rectangular cross sectional upper and lower sections 54 and 56, respectively. The lowermost cross-section side of section 54 has a length thereof greater than the cross-section length of the uppermost cross-section side of section 56, thereby forming an interlocking slot shoulder 58 along the common plane of such sides.

Weight alignment bars 34 extend axially along rows 26 in a plane in substantial alignment with the lowermost surface of portion 50. Alignment bars 34 have C shaped sections 59 spaced at intervals along the length thereof corresponding to the spacing of weights 32 along rows 26. The width of bar 34 at the web 60 of C sections 59 is such that in final interlocking assembly, web 60 is seatable on shoulder 58. The thickness of web 60 is less than the cross-section width of slot section 56.

To assemble the wire stabilizing frame 29: slide ferrule 48 of adjacent wires 20 into slots 40 of respective weights 32 until such ferrules are seated in respective seat portions 46; align bars 34 with weights 32 of respective rows 26 such that the flanges 62 of C" sec tions 59 extend in a horizontal transverse direction to the longitudinal axis of weights 32 and each C section 59 is oriented with an interlocking slot 52; and move bar 34 upwardly thereby entering C sections 59 into respective slots 52. When the web 60 has been moved sufficiently upward into slot section 56 (see bar position A on FIG. 4) bar 34 is rotated downwardly (see bar position 8" on FIG. 4) approximately 90 from the initial aligning position and then seated on slot shoulders 58 such that the flanges 62 of the C sections are extending downwardly.

After interlocking the weights 32 of respective rows 26 by means of bars 34, alignment spacer bars 36 are positioned and field bolted or welded to bars 34 thereby stabilizing rows 26 with respect to one another. It is to be noted that a single bar 34 need not extend the entire length of a row 26 but rather two or more bars 34 can be used within one row 26. 3

FIG. 5 illustrates another embodiment of a weight 32 of the present invention. Inasmuch as this embodiment closely resembles weight 32 described hereinbefore, like elements will be given the same reference numerals and similar elements will be given the same reference numerals primed. I

The principle difference in structure between weight 32' and weight 32 resides in the fact that weight 32' has a pair of spaced interlocking portions 50 rather than a singular interlocking portion 50. As shown respective interlocking portions 50' extend axially inward from each axial end of weight 32 and the respective inner ends of such portions 50' are axially spaced from one another. Such spaced portions 50 provide greater rotational stability in the event of the failure of one of the wires 20 which support a weight 32. Portions 50 have respective axially extending interlocking slots 52' therethrough and as such the assembly of a wire stabilizing frame 29 using weights 32' is essentially the same as the assembly of such frame discussed hereinbefore with reference to weights 32. Alignment bars 34 can have C shape sections 59 which extend between both portions 50 or a singular C shaped section for each portion 50. v

A significant feature of this invention is the particular structure of weights 32 which allows the simplified assembly of such weights to wires 20 and interlocking bars 34. By following the principles taught by this invention, one skilled in the art can achieve the hereinabove mentioned feature with alterations to the preferred embodiment hereinbefore described, for example: weights 32 can be structured such that individual weights are supported by a single wire 20 or three or more wires 20 rather than the two wire support, illustrated; rows 26 need not necessarily run in a direction parallel to the flow of gas but can be arranged perpendicular or diagonal thereto; depending on operation conditions, spacer bars 36 may not be required; and the slots in the weights and also the crosssectional configuration of such weights can be altered from those described.

The description herein does not limit the structure of this invention and the invention is defined by the scope of claims set forth hereinafter.

What is claimed is:

1. An electrostatic precipitator comprising: a stationary frame means; a plurality of spaced vertical wire electrodes arranged along an axis and supported at the upper ends thereof by said frame means; a plurality of weights carried by said electrodes adjacent the lower ends thereof; an elongated alignment bar means supported only by said weights; and each of said weights being supported by a plurality of said electrodes and having integral means cooperable with spaced means on said alignment bar means, respectively, to maintain interlocking engagement therebetween and retain said electrodes in a selected spaced relationship along said axis.

2. 'An electrostatic precipitator as specified in claim 1 wherein said weights are arranged along a plurality of substantially parallel axes and a respective alignment bar means extends along each of said axes.

3. An electrostatic precipitator as specified in claim 2 wherein transverse brace means extend between at least two of said axes and said brace means are fixedly secured to respective alignment bar means of said axes.

4. An electrostatic precipitator as specified in claim 1 wherein said alignment bar means has transverse rigidity to prevent swinging of said plurality of weights relative to each other.

5. An electrostatic precipitator as specified in claim 4 wherein said weights are spaced apart along a respective alignment bar means to provide substantially equal tension on all of the electrodes along each of said axes.

6. An electrostatic precipitator as specified in claim 2 wherein transverse brace means extend between at least two of said axes and said brace means are fixedly secured to respective alignment bar means of said axes.

7. An electrostatic precipitator as specified in claim 1 wherein said integral means include an opening through each of said weights and at least a portion of said spaced means are insertable within said openings.

8. An electrostatic precipitator as specified in claim 7 wherein said opening comprises a downwardly open slot communicating with a transversely enlarged chamber such that a shoulder is formed at the plane of intersection of said slot and chamber, said shoulder being of a configuration for seating engagement with the portion of said spaced means insertable within said opening.

9. An electrostatic precipitator as specified in claim 1 wherein said integral means comprise: an interlocking portion depending downwardly at the lowermost end of each of said weights; and a. respective opening extending only through said interlocking portion in the direction of said axis.

10. An electrostatic precipitator as specified in claim I wherein each of said weights is carried by at least two of said electrodes.

1 1. An electrostatic precipitator as specified in claim 1 wherein said integral means comprises a downwardly open slot communicating with a transversely enlarged chamber. 

1. An electrostatic precipitator comprising: a stationary frame means; a plurality of spaced vertical wire electrodes arranged along an axis and supported at the upper ends thereof by said frame means; a plurality of weights carried by said electrodes adjacent the lower ends thereof; an elongated alignment bar means supported only by said weights; and each of said weights being supported by a plurality of said electrodes and having integral means cooperable with spaced means on said alignment bar means, respectively, to maintain interlocking engagement therebetween and retain said electrodes in a selected spaced relationship along said axis.
 2. An electrostatic precipitator as specified in claim 1 wherein said weights are arranged along a plurality of substantially parallel axes and a respective alignment bar means extends along each of said axes.
 3. An electrostatic precipitator as specified in claim 2 wherein transverse brace means extend between at least two of said axes and said brace means are fixedly secured to respective alignment bar means of said axes.
 4. An electrostatic precipitator as specified in claim 1 wherein said alignment bar means has transverse rigidity to prevent swinging of said plurality of weights relative to each other.
 5. An electrostatic precipitator as specified in claim 4 wherein said weights are spaced apart along a respective alignment bar means to provide substantially equal tension on all of the electrodes along each of said axes.
 6. An electrostatic precipitator as specified in claim 2 wherein transverse brace means extend between at least two of said axes and said brace means are fixedly secured to respective alignment bar means of said axes.
 7. An electrostatic precipitator as specified in claim 1 wherein said integral means include an opening through each of said weights and at least a portion of said spaced means are insertable within said openings.
 8. An electrostatic precipitator as specified in claim 7 wherein said opening comprises a downwardly open slot communicating with a transversely enlarged chamber such that a shoulder is formed at the plane of intersection of said slOt and chamber, said shoulder being of a configuration for seating engagement with the portion of said spaced means insertable within said opening.
 9. An electrostatic precipitator as specified in claim 1 wherein said integral means comprise: an interlocking portion depending downwardly at the lowermost end of each of said weights; and a respective opening extending only through said interlocking portion in the direction of said axis.
 10. An electrostatic precipitator as specified in claim 1 wherein each of said weights is carried by at least two of said electrodes.
 11. An electrostatic precipitator as specified in claim 1 wherein said integral means comprises a downwardly open slot communicating with a transversely enlarged chamber. 